Rogue Cronus Magnum III

Discussion in 'Audio Hardware' started by bajaed, Jan 1, 2019.

  1. Megamoz

    Megamoz Active Member

    Location:
    UK
    Hello,

    Can anyone tell how you connect speaker cable into the binding post on Cronus Magnum III, I mean I can’t see + or - signs binding posts.

    Thank you.
     
  2. avanti1960

    avanti1960 Forum Resident

    Location:
    Chicago metro, USA
    yes, the (+) and (-) symbols are molded into the back of the case just above the terminals. the symbols are raised but are black on black and difficult to see, especially once you get it on the rack and can't move it so easily. interesting that the manual does not balloon call out the +/- terminals either.
    i use a small mirror and flashlight to help me see the back connections of my components as a tip.
    the (+) terminals are the left post of each pair when viewed from the front of the amplifier.
     
  3. Doctor Fine

    Doctor Fine "So Hip It Would Blister Your Brain"

    Does anybody know if Rogue kept the same pass through outlet on the back of the III?
    My Cronus II has a great setup for when you don't want to turn on the tubes because you want to conserve them---
    It lets you turn on your headphone amp and play a line level source using an RCA jack pass-through on the back of the amp.
    This pass-through is always active---even when the amp is OFF.
    Lots of times in my office/control room I want to listen on line without firing up my tube amp.
    I have a pair of electrostatic Koss ESP-950s with their amp plugged into the back of the Cronus using line out.
    I hit the power button on the phones E90 headphone amp and have a perfect preset volume level for late night listening.
    AND I DON'T HAVE TO TURN ON THE CRONUS AMP TO LISTEN.
    Plus the Cronus also has active output variable RCAs (one pair) to drive a pair of subs---which is awesome.
    I think that's pretty damn cool.
    Little things excite me at my age.
    The Rogue Cronus is like a great date where you get to third base.
    Or at least I vaguely remember getting to third base back in the day...
    My two cents.
     
  4. Robert M.

    Robert M. Forum Resident

    Red is positive, black is negative (audio only).

    Robert
     
  5. Megamoz

    Megamoz Active Member

    Location:
    UK
    Hello again,

    As I am new to the tube amp world, I have few newbie questions and I would appreciate to know your opinion and experience.

    -The operating temperature feels like noticeably higher compared to other types of amps, such as Yamaha stereo amp, and there's a certain type of smell when the device is on, is this the case with your amp?

    -The light is clearly visible in the left and the right power tubes (12AU7). However, the light in the center (12AU7) and other two power tubes (12AX7) is very dull. Do you observe the same on your amp?

    -Even when the volume is completely off, there's this "hiss" sound coming out of the speakers. Does your amp produce the same hiss sound?

    Thank you very much.
     
    trd likes this.
  6. JNTEX

    JNTEX Lava Police

    Location:
    Texas
    Tube amps run hot. Do you have a temp gun handy for readings?

    Tubes vary.

    No.
     
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  7. bajaed

    bajaed Forum Resident Thread Starter

    Location:
    USA
    The amount of tube/filament glow can vary. As long as the power tubes are biasing correctly you should be fine.

    I don't think you should be hearing a hiss w the volume turned down tho.
     
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  8. trd

    trd Forum Resident

    Location:
    Berkeley
    Do you mean volume turned all the way down on the amp? Or do you mean with the amp volume up but no music playing?

    If you mean the latter then that can be normal and there are various potential sources for that issue and related fixes.

    If you truly have the volume turned all the way down on the amp and have hiss playing through the speakers then I’m at a loss
     
    Last edited: Sep 20, 2019
    bajaed likes this.
  9. Doctor Fine

    Doctor Fine "So Hip It Would Blister Your Brain"

    Tube amps make some heat while "idling" and the Cronus I have makes enough to warm up my room a bit.
    As for hiss---that will depend on which preamp tubes you have in it.
    The center 12AU7 is most susceptible to noise.
    I had to change mine out with another spare tube as I looked for the lowest noise possible.
    Now my Cronus is extremely quiet and the tube I am running (a Mullard) is better sounding than the stock JJ that was in there.
    At full blast (2 o'clock on the dial) you can not hear a peep at my chair when on any line input.
    The phono section on the other hand has a slight bit of hum and hiss because it adds extra gain into the signal---but it is a great little phono pre considering it came for "free" with the unit.
    I'm going to stay with the existing phono section and not spend money on an outboard phono pre.
    It is good enough that the signal competes with a two thousand dollar DAC tone-wise so that's good enough to run it with moving coil transformers and a line contact LOMC cartridge.
    Tubes sometimes need to be swapped around to get a tube amp to perform at highest level.
    The phono pre is all solid state so tube swapping won't improve it.
    Overall this amp is a lot of bang for the buck as it sounds better than anything I have heard (transistor or tube) at anywhere near its price point.
    It is very "open" sounding and has lots of control flexibility with all those outputs and Rogue will add a mono switch if you want one.
    Great product from a great company.
    My two cents.
     
    bajaed, trd, Megamoz and 1 other person like this.
  10. Megamoz

    Megamoz Active Member

    Location:
    UK
    The amp is new and I have the stock preamp tubes. By the "center 12AU7", you mean three of them, and you replaced all three? And it was exactly which Mullard model?

    Thank you.
     
  11. Doctor Fine

    Doctor Fine "So Hip It Would Blister Your Brain"

    The 12AU7 in the center of the amp right below the meter is the preamp tube that impacts tone/hiss/hum the most.
    The other preamp tubes are for input stage and driver stage and have less impact although many here on the forum have found slight improvements by swapping those also.
    But that center tube is a big deal.
    As for exactly which Mullard AU7 to buy there are lots of postings already on here to help you find old tubes.
    Every single tube is different from others even in the same production run---so I keep a drawer full of spares from different brands (but all well regarded by experts) and swap until I get lucky.
    Do a search and go buy a couple to play with to lower hum/hiss/crackle and improve tone.
    It's FUN.
    That's the fun part of tube amps!
     
  12. avanti1960

    avanti1960 Forum Resident

    Location:
    Chicago metro, USA
    that has been my experience as well. i had a very expensive NOS amperex 12Au7 tube go noisy and microphonic after a year or so. good thing is you can buy them with noise screening.
     
  13. Megamoz

    Megamoz Active Member

    Location:
    UK
    Is removing preamp tubes easy? 'Cause, it feels like they are fixed and a tool or something is required to replace, while output tubes can be easily removed.
     
  14. bajaed

    bajaed Forum Resident Thread Starter

    Location:
    USA
    Slowly wiggle it while pulling up a little and it will loosen up. Match the pins on the tube to the holes in the socket and gently work the new tube down.
     
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  15. Megamoz

    Megamoz Active Member

    Location:
    UK
    So, my local dealer sent me a couple of spare tubes and I replaced the stock one with one of those. The result: that outrageous hiss sound is mostly gone. It is only audible if you’re near the speaker, like 10 cm.
     
    Mfisher702 likes this.
  16. SandAndGlass

    SandAndGlass Twilight Forum Resident

    That can be expected with any typical tube amplifier.
     
    mike catucci likes this.
  17. Megamoz

    Megamoz Active Member

    Location:
    UK
    Even when the volume is completely down? I also noticed that when I press mute on the remote, it’s dead silent.
     
  18. honestabe316

    honestabe316 Analog Rebel

    My cm2 is very quiet hums drive me crazy...it shouldnt be there if its enough to bother you. Thats my own opinion though
     
  19. Megamoz

    Megamoz Active Member

    Location:
    UK
    I think, now I can live with it.

    As SandAndGlass suggested, it all comes down to the preamp tube I reckon.
     
  20. honestabe316

    honestabe316 Analog Rebel

    Ive tried gold lions, mulards,jj's and current new production telefunken black diamonds by jj and no hum... i live in a townhouse too so electric runs through 7 units....still no hum... but if u can live with it thats good
     
    trd likes this.
  21. Conezays

    Conezays Forum Resident

    Location:
    Canada
    Any other impressions from those who upgraded from CM2 to 3? I have a CM2 myself and very happy with it. I primarily use it for listening to records and am curious how improved the new phono is on the CM3. Cheers!
     
  22. SandAndGlass

    SandAndGlass Twilight Forum Resident

    From the Rogue website, RE: upgrades: Cronus Magnum II to Cronus Magnum III $1,295.

    I own three Rogue tube amps. but I don't see the point in paying this much for an unnecessary upgrade.

    I would prefer instead to just buy the external phono preamp that was exactly what I wanted.

    I have the original CM1 and it sits behind the TV, away from any of the turntables. As such, I have never used its internal phono-pre.

    But then, it was never my intention to.
     
    Mfisher702 and Conezays like this.
  23. honestabe316

    honestabe316 Analog Rebel

    I upgraded the caps and resistors in my CM2... sounded like a move that would improve things... i have a tube phonostage so never really needed the cm2 phonostage... i had a tube headphone amp too but used it like 3 times in a year so sold it last week and bought a sphinx for my second system.

    $1295 does seem a lot to me as well, but for those who utilize their cm's phonostage and headphone amp then maybe its not such a bad option.

    Before i got the upgrade to the cm3 i would much rather add a couple hundred to the $1295 and instead pick up a used chinook, Ares, allnic h1201 or a Black Ice f159 (jolida) phonostage....to me that would be the best bang for those kind of dollars...

    Honestly, i wish you could buy a Cronus Magnum without the phonostage and headphone amp, or be able to choose only the phonostage or only the headphone amp...

    I would be completely fine with my integrated simply having the preamp and amp and have them either lower the price, or use the savings to use higher quality parts... i guess i get that the phonostage and headphone amp are selling points for many people... but i really wish you could order a cm customized to what you need.
     
  24. Conezays

    Conezays Forum Resident

    Location:
    Canada
    Thanks for the replies. I primarily use mine for phono; have only used the headphone out a handful of times. Very happy with how it sounds overall, but would have to hear other phonos in here to properly compare (the amp is going into KEF Reference 1's).
     
    honestabe316 likes this.
  25. Conezays

    Conezays Forum Resident

    Location:
    Canada
    I think I will end up making the upgrade as the improvements are all fairly attractive for what I use it for.
    The turnaround time will be rough without a nice amp though. :cussing:
     

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